侵染野茼蒿引起黄脉症状的联体病毒的分子鉴定

Molecular Identification of Geminiviruses Inducing Vein Yellowing in Crassocephalum crepidioides

采自云南元江的野茼蒿表现为明显的叶脉黄化症状,从中检测到的病毒分离物分别命名为YYJ1,YYJ2,YYJ3。利用已经报道的联体病毒通用引物PA/PB对多株野茼蒿样品进行PCR检测,扩增到约500 bp大小的特异性基因片段。扩增产物序列测定表明,YYJ1,YYJ2与云南烟草曲叶病毒(Tobacco leaf curl Yun-nan virus,TbLCYNV)各分离物的同源性最高,分别为96%,98%。YYJ3与景洪野茼蒿黄脉病毒(Crass-ocephalum yellow vein virus-Jinghong)的同源性达98%。初步断定云南烟草曲叶病毒与景洪野茼蒿黄脉病毒是侵染元江野茼蒿的两个主要病毒。同时,利用扩增联体病毒卫星DNAβ的引物beta01/beta02对不同染病植株进行检测,未检测到联体病毒的卫星DNAβ。

Crassocephalum crepidioides Samples with vein yellowing symptom were collected from Yuanjiang, and three virus isolates, namely YYJ1, YYJ2 and YYJ3, were isolated from the diseased plants. PCR detection was conducted and a -500 bp fragment was amplified from diseased tissues with the reported primers PA/PB, the PCR fragment was cloned and sequenced. Sequence analysis result showed that YYJ1, YYJ2 shared 96% and 98% nucleotide homogeneity with the Tobacco leaf curl Yunnan virus （TbLCYNV） separately, and YYJ3 shared 98% nucleotide homogeneity with Crassocephalum yellow vein virus-Jinghong. It was indicated that TbLCYNV and Crassocephalum yellow vein virus-Jinghong were two viruses found in Crassocephalum crepidioides from Yuanjiang. No fragments could be detected from disease tissues by PCR identification with primers beta01/beta02.